Smart Doorbell (3)

DRAFT

This is part three of the Smart Doorbell project.

Step 21. Hot glue motion sensor

The motion sensor has a dome. The dome comes off easily. So, instead of putting the sensor in from the front, I put it in from the back. To fit, I had to clip one edge so it was flat to the case.

Hot glue the motion sensor in place. Just enough to keep it in place. The RaspiAudio and Raspberry Pi Zero still need to be inserted.


Step 22. RaspiAudio and Raspberry Pi

Put the RaspiAudio hat on the Raspberry Pi Zero and then hot glue the RaspiAudio in place so the speakers and microphone align with the holes in the face plate.

I am terrible at soldering. So, this was challenging for me. I learned it really hurts when I tried steadying the heating element of the soldering iron with a free finger. Neosporin helped heal the wound. Here is a great soldering guide.

The wires need to be trimmed very close, and the stripped end of the wire attaching to the Raspberry Pi needs to be really short (less than 1/8 inch). I used Blue Tack to hold the wires in place while soldering.

Solder the wires from the motion sensor, LED and push button as shown in Step 12 in Part 2

Step 23. Insert Ribbon Cable from Camera Module into Raspberry Pi Zero

At this point, the camera module and RaspiAudio should be hot glued to the face plate. And the RaspiAudio should be mounted on the Raspberry Pi Zero.

Insert the 22 pin ribbon cable into the Raspberry Pi Zero. Gently push the ribbon cable connector in place.

Do not fold, but gently bend and push the ribbon cable under the Raspberry Pi. This will allow the ribbon cable to fit within the box.

Step 24. Glue Gun Strings

I always end up with glue gun strings. Cut these off.

*** STOPPED HERE ***

Have button, camera, motion sensor, switching regulator ... what can I build

    • add detailed drawing of front plate and bottom of case

    • upgrade github with latest version of scripts

    • In script on RPi, move videos, photos and microphone recordings to sub directories

    • microphone - add to script

    • change previous in this guide to reflect just having one script instead of multiple scripts

    • add video capture with date and time stamp

    • add an option to disable alert on motion detection

    • might only want to light when motion is detected

    • might only light from 6am-12am or if motion is detected time should be configurable

    • add an option to disable alert on doorbell push

    • add alexa/echo

    • add video capture with date and time stamp

    • add inside chime

    • one-way video

    • two-way communication

    • switching regulator

    • move video or photo to external storage device

add directions for box bottom to doorbell case page - take off ring outside, measure outside holes and drill holes in box - add these instructions to the box creation

https://rayshobby.net/wordpress/24vac-to-5vdc-conversion/

https://rayshobby.net/wordpress/24vac-to-5vdc-conversion/

AC-DC buck converter

  • NACRO AC-DC to DC Converter AC 16-28V DC 9V 12V 24V 36V 8-40V Step Down to 5V 3A 15W Power Supply Module

  • 2Pcs AC/DC to DC Step Down Buck Converter AC 5-30V DC 5-48V 24V 36V 48V to DC 2.5-35V 12V Voltage Regulator Board 2A Adjustable Volt Power Supply Module Delinx

might need to change example above about how I chose switching voltage regulator

when I took apart ring doorbell, the lines coming in were AC and not DC

Step N. Create a Switching Voltage Regulator

The doorbell chime transformer provides 16 volts, but the Raspberry Pi should only receive 5V. So, either a step down or switching voltage regulator is required. The regulator needs to provide about 300mA.

A switching regulator dissipates less heat and uses less energy. I found the schematic below on ElectroSchematics and it meets all of my requirements.

The plan is to put the regulator in the chime. There will be some voltage drop because of the resistance in the wires from the chime to the doorbell.

Step Na. Power Supply and USB Connector

The Female Micro USB Connector I used only has 4 pins. Pins 4&5 of a standard Micro USB are hardwired together. Since I only plan to use wire and ground this does not matter.

Step M. Power Supply and USB Connector

The Female Micro USB Connector I used only has 4 pins. Pins 4&5 of a standard Micro USB are hardwired together on my Micro USB. Since I only plan to use the 5v wire and ground (Pin 1), this does not matter.

Cut USB to Micro USB cable and figure out which wires are ground and which are 5v. I used a wire cutter and exacto knife to get down to the wires. In my USB cable, Red is Ground and Black is 5V. Your cable will differ.

Cut two 3 to 4 inch flexible wires. Strip 1/8 inch on one end 1/4 inch on the other end. Solder the wires at right angles to pads (Pin 1 = Gnd and Pin 4 = 5v). I am going to use white for ground and black for power. In later steps, these wires will come out the back side of the box and connect to the chime's transformer.

With the USB power not plugged in, do the following:

Twist the ends of the USB cable to the wires on the Micro USB. Insert the Micro USB Connector into the Raspberry Pi

Once the above is complete, plug the USB cable into an outlet, which should power up the Raspberry Pi. Login to see if it is still working. Shut down the Raspberry Pi using the command.

$ sudo shutdown -h 0


USB to Micro USB cut apart

Micro USB wires connect to USB power supply

Micro USB wires at right angles to pads

Step XD. Mechnical Chime or should I use Wi-Fi Chime

Broan NuTone Model BK115LWH

Mechanical Chime

16v C905 transformer

https://www.broan-nutone.com/en-us/product/doorbells/bk115lwh


Transformer location is in the attic by the AC units

Which circuit breaker goes to transformer

Step XQ. Start all over [about 4 times]

My last step in creating a project like this is to take everything apart. I start by reflashing the MicroSD Card and start over. I do this to ensure I haven't accidentally skipped a step, or installed something during my prototyping that is required but not listed in the steps.

References:

Considered and Rejected:

Power Bank: Insert a Power Bank between the chime and the doorbell. If power goes out, then the Raspberry P's MicroSD Card won't get corrupted. Power Banks require dual ports, and must be able to charge and power the RPi at the same time. The reason to reject this idea is a Power Bank is charged from a wall outlet and neither the doorbell not the chime have a nearby outlet. Link to very small power supply.

RPi 3b+/4: I like the form factor of the new generation of doorbells. The older generation would have fit a Raspberry Pi 3/4. Dimensions: 85 x 56 x 17mm, 3.35 x 2.2in. For example, Ring Gen 2 dimensions: 4.98 x 2.4 x 1.10in. Initially, I didn't think I could find small enough parts or a case to fit everything.

I was leaning towards the hard plastic case for a RPi 3 B+/4:

Aluminum Case for Raspberry Pi - this might have issues with Wi-Fi propagation

          • 97.79 x 64.01 x 34.29 m

          • ~3-7/8 x 2-1/2 x 1-3/8 in

          • Needs to be painted black

Polycarbonate for Raspberry Pi

          • 114.30 x 66.80 x 52.07 mm

          • 4-1/2 x 2-5/8 x 2-1/16 in

Hard Plastic Case

          • 107.95 x 66.80 x 32.26 mm

          • 4-1/4 x 2-5/8 x 1.1/4 in